This disclosure is generally directed to imaging members, devices, photoreceptors, photoconductors, and the like. More specifically, the present disclosure is directed to rigid or multilayered flexible, belt imaging members, photoconductors, or devices comprised of a supporting medium like a substrate, a photogenerating layer, an optional undercoat or hole blocking layer usually situated between the substrate and the photogenerating layer, and at least one charge transport layer, wherein at least one is from 1 to about 5, from 1 to about 3, 2, one, and the like, such as a first charge transport layer and a second charge transport layer, a hole blocking layer, an optional adhesive layer, and an overcoating layer containing a fluoroalkyl ester, and wherein at least one of the charge transport layers contains at least one charge transport component, and a polymer or resin binder, and where in embodiments the resin binder selected for the hole blocking layer is a known suitable binder including a binder that is substantially insoluble in a number of solvents like methylene chloride, examples of these binders being illustrated in copending application U.S. application Ser. No. 11/593,658, the disclosure of which is totally incorporated herein by reference.
In embodiments, the overcoating layer is comprised of a polymer like those as illustrated herein with reference to the resin binder polymers, a fluoroalkyl ester, and an optional charge transport compound, and more specifically, the overcoating layer is comprised of a mixture of a suitable polymer, a fluoroalkyl ester, and an optional charge transport component.
Photoconductors containing fluorinated polymers, such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) in the ACBC layer, in the charge transport layers or in the overcoating layer can be difficult to prepare, and uniform and stable dispersions thereof usually cannot be obtained; the layers containing the aforementioned fluoropolymers tend to charge up triboelectrically due to the rubbing of this layer against, for example, backer plates and rollers in, for example, a xerographic printing machine, resulting in electrostatic drag force that adversely affects the process speed of a photoconductor present in the machine; fluoropolymer particles or debris adversely affect other related systems in the machine; and there can be charge accumulation on the ACBC surface or the overcoating layer. Low surface energy overcoatings are desirable for photoconductors to permit excellent wear resistance characteristics, emulsion aggregation toner cleanability, and anti-filming properties, all of which are not readily achievable with the incorporation of fluoropolymers in the overcoating layer. Also, for flexible belt photoconductors is the unwanted LCM that is generated from a fluoropolymer (PTFE/surfactant dopants) since unlike in drum photoconductors, the charge transport layer degrades or wears from blade cleaning in belt photoconductors, thus conductive species tend to accumulate on the surface resulting in LCM. These and other disadvantages are avoided or minimized with the photoconductors of the present disclosure that contain a fluoroalkyl ester in the ACBC, and/or the charge transport layer, and/or the overcoating layer.
Also included within the scope of the present disclosure are methods of imaging and printing with the photoconductors illustrated herein. These methods generally involve the formation of an electrostatic latent image on the imaging member, followed by developing the image with a toner composition comprised, for example, of thermoplastic resin, colorant, such as pigment, charge additive, and surface additive, reference U.S. Pat. Nos. 4,560,635; 4,298,697 and 4,338,390, the disclosures of which are totally incorporated herein by reference, subsequently transferring the image to a suitable substrate, and permanently affixing the image thereto. In those environments wherein the photoconductor is to be used in a printing mode, the imaging method involves the same operation with the exception that exposure can be accomplished with a laser device or image bar. More specifically, the flexible photoconductor belts disclosed herein can be selected for the Xerox Corporation iGEN® machines that generate with some versions over 100 copies per minute. Processes of imaging, especially xerographic imaging and printing, including digital, and/or color printing, are thus encompassed by the present disclosure.
The photoreceptors illustrated herein, in embodiments, have extended lifetimes; possess excellent, and in a number of instances low Vr (residual potential); and allow the substantial prevention of Vr cycle up when appropriate; high sensitivity; low acceptable image ghosting characteristics; and desirable toner cleanability.